Shear mode actuators made from ceramic piezoelectric materials such as lead zirconate titanate-based ceramics (PZT) are not widely used in industry or defense applications. This is because there is no simple and effective strain amplifying mechanism associated with these ceramic piezoelectric materials. The shear piezoelectric constant d.sub.15 is larger than the linear constants d.sub.31 and d.sub.33 for materials such as PZT. A high electric (E) field applied to the ceramic piezoelectric material is required for strain generation. The E field for strain generation is on the order of 1 Kilovolt per centimeter for PZT material thickness. It is desirable to decrease the voltage required for the high E field, while increasing the shear angle of the ceramic material used. Currently, increasing length and decreasing thickness for a given volume of PZT material allows for reduction of the required voltage to drive the E field needed for strain generation. It also allows for the generation of a large shear generalized displacement for any given voltage. But, increasing length and decreasing thickness of the PZT actuator produces sizing problems and decreases actuator force otherwise available. These problems are compounded by the shear elastic stiffness C.sub.44 which controls the blocking force being significantly lower than the linear constant C.sub.11.
It is an object of the present invention to provide a PZT actuator which generates large shear angles at low applied voltages, maintains a compact size and can be used in both linear and shear mode applications.